Two cases of advanced gastric cancer involving the pyloric ring which was difficult to diagnose endoscopically

Abstract

We report two cases of advanced gastric cancer involving the pyloric ring, which was difficult to diagnose properly by endoscopic examination and biopsy. Case 1 : A 70 year-old male with pyloric stenosis. Six biopsy specimens were taken from the lesion, and only one of them pathologically showed gastric cancer. Case 2 : A 69 year-old male with a type 2 gastric cancer involving the pyloric ring. The first endoscopic examination was performed 5 months before operation, but was diagnosed as benign gastric ulcer, and biopsy specimen also showed no evidence of cancer. Endoscopic examinations were performed again twice thereafter, and only one biopsy specimen showed cancer. The difficulty in getting precise diagnosis is due to the fact that most of the cancer cells exist in the submucosal layer or deeper. And endoscopists tend to take biopsy from the ulceration in the center of the lesion, because it is easy to reach the center of the lesion by biopsy forceps. But as for type 2 gastric cancer involving the pyloric ring, the ulceration is closed by the surrounding wall covered with normal mucosa due to the stricture of the ulcer bed. For this reason, most of the biopsy specimens from such lesions are normal mucosa. Endoscopists should be careful in the diagnosis of type 2 gastric cancer involving the pyloric ring.